The invention is directed to structural frameworks and the like, comprised of elongated, strut-like structural elements rigidly joined at points of intersection to form a rigid three-dimensional structure. Such structural frameworks are used to advantage wherever lightweight, rigid frame structures are utilized. Among other uses of such structural frameworks is in the manufacture of customized or prototype machinery, for example.
It is known to construct structural frameworks utilizing a plurality of strut-like structural elements joined together by clamps or other connecting means to form a rigid, three-dimensional structure, which may be of a permanent or temporary character. In accordance with the present invention, a novel three-way clamp element is provided, for use in the construction of such structural framework assemblies. The clamp is provided with a through bore and two intersecting shouldered bores, each arranged to receive, with a relatively minimum clearance, a separate strut-like element. The two shouldered bores are disposed at an angle to each other of less than 180.degree. (typically 90.degree.) and their axes define a plane intersecting with the axis of the through bore. The body of the clamping member is formed with a slot, which lies in or near the plane defined by the shouldered bores. The slot intersects with the shouldered bores, along their full length, and also intersects with the through bore. The arrangement is such that the body of the clamp is formed with a pair of opposed, cantilever extension portions, the free ends of which are spaced apart by the width of the slot. When structural elements are received in each of the bores, all of the structural elements can be simultaneously clamped and secured by applying a compressive force to the opposed cantilever extension portions of the clamping body. Typically and advantageously, the compression force may be applied by a single bolt which extends through one of the portions and is threadedly engaged with the other and can be tightened quickly after positioning of the structural elements in the clamp body.
The clamping device of the invention greatly expedites the assembly of structural frameworks and is particularly useful for customized or prototype structures because of the facility with which structural elements may be assembled, clamped, and if necessary, released for adjustment.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawing.